Europa’s Ocean Secrets, Gravitational Waves & Black Hole Mysteries | Space Nuts: Astronomy...

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Kind: captions
Language: en

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Hi, Andrew Dunley here. Fred and I are


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taking a little bit of a break over the


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Christmas New Year period just to catch


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our breath. We'll be back uh sometime


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around mid January. In the meantime,


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we've been digging through the archives


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at some of the most perplexing and


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popular episodes that we've done in


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recent times. So, sit back and enjoy.


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>> 15 seconds. Guidance is internal. 10 9


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ignition sequence start. Space Nuts.


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>> 5 4 3 2


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>> 1 2 3 4 5 2 1


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>> Space Nuts.


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>> Astronauts report. It feels good.


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>> Hi there and thanks for joining us on


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the Space Nuts podcast. My name is


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Andrew Dunley, your host. And joining


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me, as always, Professor Fred Watson,


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astronomer at large from the department


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of da da da da da. It's a pretty long


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title. That's what we'll call it from


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now on. Good day, Fred. You could call


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me the AAL because AAL.


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>> Yeah. When I was when I was astronomer


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in charge, I was AIC.


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The only trouble is AAL actually has


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another significant meaning in


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Australian astronomy because it doesn't


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only stand for astronomer at large. It


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also stands for Astronomy Australia


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Limited. So, uh, just throw that idea


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out. That's a rubbish idea. It'll just


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be a Yeah,


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>> I was once given the title URS.


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But anyway, um,


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some people will understand that.


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>> Yeah. You've got lovely friends, haven't


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you?


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>> I've got a lot of good friends. Yes.


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>> Yeah. Yeah.


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>> Now, today we're going to talk about


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some very exciting things. It looks like


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black holes are still in people's minds.


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So, we're going to be talking about um a


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couple of questions that have come in


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from people about infinite density. Uh,


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density. I keep getting it mixed up with


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destiny. I don't know why. might have


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been a Back to the Future movie that


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confused me on that front. Uh, and


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issues photographing a black hole. Why


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were they issues at all? And another


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question about space travel and near


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light speed travel. Uh, we're also going


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to look at um the cause of a


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gravitational wave that was detected


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recently. This is exciting because they


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think they've pinpointed an actual


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cause.


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And we're going to start off today,


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Fred, by talking about this rather


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exciting mission that's one step closer


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to happening. A mission to Jupiter's ice


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moon Europa. And that's what we'll start


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with this uh well this afternoon, this


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morning, tonight, this evening,


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yesterday,


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whenever


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>> whenever it is. Yeah, it's Yeah. So


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look, a terrific story, very good news


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from uh NASA that they um the powers


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that be within NASA have uh given the


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go-ahad um for a mission called Europa


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Clipper, which is is one of the uh


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missions that's been uh postulated or or


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sorry proposed is a better word for um


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exploring the moons of the outer


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planets. There are a number that are


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kind of on the on the table at the


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moment. Some further advanced than


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others, but Europa Clipper is pretty


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well advanced and as you can tell it's


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target, its main target is Jupiter's


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moon Europa, which is one of these um


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ocean moons, uh ice ocean moons. Uh we


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believe it has a covering of ice, and we


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don't know whether it's thin ice or


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thick ice. So that will be one of the


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things that Europa Clipper would find


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out. um and an ocean underneath it and


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and a rocky core. Uh so Europa Clipper I


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think they are talking about having it


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ready for launch in 2023 which is um you


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know fantastic if if they can do that.


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That's right. Uh but apparently that's


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um that's the the the the baseline


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commitment as it's called supports a


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launch readiness date by 2025. Um, it's


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all being done at the Jet Propulsion


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Laboratory in Pasadena. That's where the


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spacecraft will be built. So, they've


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got the go-ahad. It's um it's got a you


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know, the next step in uh in approval


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from NASA, which I think is a pretty


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solid one. So, I think we you and I in


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2025


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will be talking a lot about Europa


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Clipper maybe. Yeah. and it and what


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will be the basis of the of the mission?


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Are they just going there to have a look


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because


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>> it is a bit like that but it's a very


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good look. Um so it's not going to land


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on Europa. It is a proposal to go into


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orbit around Europe actually to go into


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orbit around Jupiter. Uh and of course


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orbiting Jupiter is always hazardous


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because of the the intense um you know


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the intense uh radiation belts that


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Jupiter has. It's got a magnetic field


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thousands of times bigger than the


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earth's and has these high energy


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radiation belts around it that threaten


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to melt the inards of spacecraft. Uh so


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like uh the Juno mission which is


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currently in orbit around Jupiter, this


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uh Europa Clipper will go into a very uh


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elongated orbit um which will give it 45


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flybys of Europa. Uh, and the altitudes


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will vary from 2,700 kilometers to 25


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kilometers. So, it will really be


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skimming over the surface.


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>> Oh, will.


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>> And it's got this huge science package


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with all the kind of, you know, the


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goubbins that you would expect to find


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on board something like that, including


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a mass spectrometer,


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uh, which basically measures, you know,


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the the weights of atoms, as you might


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guess. Uh it um that is interesting


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because Europa like Saturn's moon


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Enceladus is thought to have although it


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hasn't really been properly confirmed


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but thought to have uh ice uh fountains


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coming out of it. Um which are water


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that's squirting up through its uh


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through its icy shell and instantly


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freezing. It's not frozen. But if you


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fly through it as Cassini did with


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Enceladus, then you can sample what the


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atomic makeup is. And so the mass


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spectrometer will help with that. Uh and


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also um it's got this ground penetrating


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radar and that's going to be crucial in


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characterizing Europa's crust um and


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revealing how much of you know the


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potential water within is oceanic as as


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is expected or whether it is just


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pockets of water as we find in


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Antarctica and indeed around the south


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pole of Mars. Will they be able to tell


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what kind of water it is?


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>> Um uh to to some extent they will. Um it


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it may require a bit of um you know


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inference from other measurements. But


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if you've got samples of ice crystals,


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uh then you can do exactly that. you can


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you know you can uh basically tell tell


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whether it's saline water or fresh water


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because you can see the you can measure


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the salt content of it. So like um


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Saturn's moon and Celadus uh which is


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actually quite rich in minerals and and


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it's the silicut in that that tells you


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that this water was once in contact with


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with rock. Uh, I think the Europa


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Clipper will be able to sample exactly


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those things too, assuming these plumes


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are real because they're then they're


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not well observed. There are there is


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evidence. I've seen images that that


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seem to show these plumes coming from


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Europa. Uh, assuming they're real, when


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they fly through, um, hopefully we will


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be able to tell what kind of water it is


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exactly.


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>> And will they be able to tell how much


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water there is underneath the surface?


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Yes, they will because that will very


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much be revealed by the um the ground


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penetrating radar in exactly the way


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that um one of the spacecraft in orbit


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around Mars. I think it was the I think


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it was might even have been Mars


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Reconnaissance Orbiter, I'm not sure,


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detected this lake of liquid water


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underneath the ice cap of the southern


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ice cap of Mars about a year ago. You


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and I spoke about it. Um, and they can


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tell exactly how much there is there


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because you you can see the boundary


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with this sort of radar. You can see the


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boundary between an ice surface and a


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water surface. And that's crucial to


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doing this. So, this mission won't


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actually be looking for life, but it


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will be looking for uh the potential for


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life to perhaps exist on a on a moon


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like this.


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>> Exactly. So, as the as the blurb um on


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the NASA website says, uh it will help


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scientists investigate the chemical


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makeup of Europa's potentially habitable


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environment while minimizing the need to


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drill through layers of ice. So, that


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what they're going to try and do is as


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much as they can from orbit.


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Um and then you know if there's like if


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they find lipids and amino acids and all


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this sort of thing in the uh in the


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plumes of ice coming coming from Europa


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then clearly the next step will be a


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lander that starts digging holes in the


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ice.


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>> Yes.


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>> I mean you know before you do that the


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first thing you need to know is how


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thick the ice is.


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>> Yes.


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>> If it's a couple of miles thick


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>> actually a couple of miles is better


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than what they're expecting.


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>> Oh is that right? more like 25 or 30


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>> miles or kilometers. That's right.


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Choose your units. Um yes. So yes, a a


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thinish layer of ice would be pretty


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pretty um good to you know to cope with.


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You could probably do that. I mean by


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thin I mean less than a kilometer


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probably.


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>> Yes. But the likelihood is it's it's


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probably more. But I guess we'll we'll


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have to wait and see.


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>> The thing is and um Europa is covered in


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all these cracks that are that are


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brownish in color. Yes,


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>> that's thought to be the effect of


00:09:49.519 --> 00:09:52.150
sunlight on brine on basically on salt


00:09:52.160 --> 00:09:54.070
water. So, you've already got a hint


00:09:54.080 --> 00:09:57.030
there that it's probably a salty ocean


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underneath the surface.


00:09:58.399 --> 00:10:00.150
>> Well, salt's probably not that uncommon


00:10:00.160 --> 00:10:02.310
in the universe really. Um,


00:10:02.320 --> 00:10:03.350
>> that's right. It's not.


00:10:03.360 --> 00:10:05.910
>> It's one of one of the base materials,


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isn't it? Uh, of course, this doesn't


00:10:08.399 --> 00:10:09.990
guarantee they're actually going to go.


00:10:10.000 --> 00:10:12.230
This is just another step forward in the


00:10:12.240 --> 00:10:14.069
approval process. It it does. It does.


00:10:14.079 --> 00:10:16.230
Correct. very longitudinal process and


00:10:16.240 --> 00:10:18.389
they have to get over a lot of hurdles


00:10:18.399 --> 00:10:19.750
before they actually hit the launch


00:10:19.760 --> 00:10:22.550
button. So, uh hopefully they're um


00:10:22.560 --> 00:10:24.630
they're going to get there and u it's


00:10:24.640 --> 00:10:26.310
it's a long trip to


00:10:26.320 --> 00:10:27.590
>> Yes, it is. That's the other thing.


00:10:27.600 --> 00:10:29.030
>> So, they got to time it right. They've


00:10:29.040 --> 00:10:30.310
got to get in the right place at the


00:10:30.320 --> 00:10:31.030
right time.


00:10:31.040 --> 00:10:33.509
>> Exactly. All of the above. That's right.


00:10:33.519 --> 00:10:36.069
So, at least what it you know, at least


00:10:36.079 --> 00:10:37.829
uh it's not a knock back. That's the


00:10:37.839 --> 00:10:38.630
good news.


00:10:38.640 --> 00:10:40.470
>> Yes, indeed. All right. Well, we'll keep


00:10:40.480 --> 00:10:42.069
an eye on this story because I'm sure


00:10:42.079 --> 00:10:43.990
there'll be more to report in the not


00:10:44.000 --> 00:10:46.630
too distant future about a mission to


00:10:46.640 --> 00:10:49.590
Europa. You're listening to Space Nuts


00:10:49.600 --> 00:10:53.430
with Andrew Dunley and Fred Watson.


00:10:53.440 --> 00:10:54.949
Let's take a break from the show to tell


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Or you can tap on the link in the show


00:12:45.040 --> 00:12:46.389
notes.


00:12:46.399 --> 00:12:48.310
>> Roger, you're here also.


00:12:48.320 --> 00:12:50.470
>> Space nuts. Now, Fred, we've uh


00:12:50.480 --> 00:12:52.069
discussed


00:12:52.079 --> 00:12:55.269
uh gravitational waves before and a few


00:12:55.279 --> 00:12:57.190
of those have been detected in recent


00:12:57.200 --> 00:13:01.030
times. Uh the problem with them is what


00:13:01.040 --> 00:13:04.870
is the cause? And now in a recently


00:13:04.880 --> 00:13:07.030
detected gravitational wave, they think


00:13:07.040 --> 00:13:10.230
they've got a candidate. That's that's


00:13:10.240 --> 00:13:11.750
right. This is so this is, you know,


00:13:11.760 --> 00:13:15.030
it's a an ongoing story. Uh what I like


00:13:15.040 --> 00:13:16.629
about this story is it's got a nice


00:13:16.639 --> 00:13:19.030
Australian component because there is um


00:13:19.040 --> 00:13:22.550
there's a a a basically a a


00:13:22.560 --> 00:13:24.230
collaboration here in Australia which is


00:13:24.240 --> 00:13:26.710
called Osgrav uh which is about


00:13:26.720 --> 00:13:28.470
gravitational waves. It's a you know


00:13:28.480 --> 00:13:30.629
kind of fairly predictable name but um


00:13:30.639 --> 00:13:32.389
it includes people from the Australian


00:13:32.399 --> 00:13:34.870
univers national university and I think


00:13:34.880 --> 00:13:36.710
University of Western Australia other


00:13:36.720 --> 00:13:38.629
places which are strong in gravitational


00:13:38.639 --> 00:13:41.829
wave astronomy. So um it's very nice


00:13:41.839 --> 00:13:43.829
that it has this Australian component.


00:13:43.839 --> 00:13:47.030
So what's the story? Well uh the large


00:13:47.040 --> 00:13:49.110
uh sorry the laser interferometer


00:13:49.120 --> 00:13:51.829
gravitational wave observatory otherwise


00:13:51.839 --> 00:13:55.110
known as LIGO um has been operating


00:13:55.120 --> 00:13:59.430
since uh 2015 in its uh sort of current


00:13:59.440 --> 00:14:01.110
state. It's actually technically called


00:14:01.120 --> 00:14:03.750
advanced LIGO because I think it took 15


00:14:03.760 --> 00:14:05.670
years of de of development to get to


00:14:05.680 --> 00:14:08.949
this stage. But that but they have uh


00:14:08.959 --> 00:14:11.990
now not quite regularly but at fairly


00:14:12.000 --> 00:14:14.710
infrequent intervals sorry fairly


00:14:14.720 --> 00:14:17.110
moderately moderate intervals let me put


00:14:17.120 --> 00:14:18.790
it that way they've been detecting


00:14:18.800 --> 00:14:21.269
gravitational wave events and for the


00:14:21.279 --> 00:14:22.790
last couple of years they've had an


00:14:22.800 --> 00:14:24.310
additional string to their bow. Remember


00:14:24.320 --> 00:14:25.750
there are two of these detectors at


00:14:25.760 --> 00:14:29.430
opposite corners of the United States um


00:14:29.440 --> 00:14:33.030
which um you need because uh otherwise


00:14:33.040 --> 00:14:34.550
you've got no idea where these things


00:14:34.560 --> 00:14:36.310
come from or even if they're real. you


00:14:36.320 --> 00:14:38.629
need to see the gravitational wave pass


00:14:38.639 --> 00:14:40.310
one and then the other with the right


00:14:40.320 --> 00:14:42.949
kind of time interval in between. Um but


00:14:42.959 --> 00:14:44.550
they've been joined in the last few


00:14:44.560 --> 00:14:47.509
years by something called uh uh Virgo


00:14:47.519 --> 00:14:49.189
which uh in fact I think it's called


00:14:49.199 --> 00:14:51.509
advanced Virgo like advanced LIGO. Virgo


00:14:51.519 --> 00:14:53.750
is an Italian gravitational wave


00:14:53.760 --> 00:14:55.350
detector. And of course having three


00:14:55.360 --> 00:14:58.150
detectors widely spread over the surface


00:14:58.160 --> 00:14:59.670
of the earth means you can pinpoint


00:14:59.680 --> 00:15:01.750
things much more accurately in in terms


00:15:01.760 --> 00:15:03.110
of the direction in which these


00:15:03.120 --> 00:15:05.269
gravitational waves come in from. tri


00:15:05.279 --> 00:15:07.189
triangulating the signal.


00:15:07.199 --> 00:15:10.470
>> Exactly. That's exactly what it is. Um,


00:15:10.480 --> 00:15:12.470
what's interesting about this one though


00:15:12.480 --> 00:15:16.870
is that the signal seems to be from a


00:15:16.880 --> 00:15:21.430
black hole absorbing a neutron star.


00:15:21.440 --> 00:15:24.310
>> Um, we actually had a false alarm on


00:15:24.320 --> 00:15:27.030
this, which is embarrassing because um,


00:15:27.040 --> 00:15:28.870
my book has just gone to the printer


00:15:28.880 --> 00:15:30.870
saying, "Yes, we've observed a neutron


00:15:30.880 --> 00:15:33.189
star being absorbed by a black hole."


00:15:33.199 --> 00:15:36.069
Um, and that that I think disappeared


00:15:36.079 --> 00:15:38.310
because it turned out to be um


00:15:38.320 --> 00:15:40.389
terrestrial noise. It was sort of, you


00:15:40.399 --> 00:15:41.750
know, so I don't know whether it was a


00:15:41.760 --> 00:15:44.069
train going underneath


00:15:44.079 --> 00:15:44.470
probably


00:15:44.480 --> 00:15:46.230
>> or Yeah, something like that. That's the


00:15:46.240 --> 00:15:48.470
usual story, isn't it? A microwave oven.


00:15:48.480 --> 00:15:51.110
Um that was earlier this year. And and


00:15:51.120 --> 00:15:54.069
that um has now gone away, but it looks


00:15:54.079 --> 00:15:57.350
as though this one might actually be the


00:15:57.360 --> 00:15:59.430
real thing, a black hole and a neutron


00:15:59.440 --> 00:16:01.670
star. Uh we've had two black holes


00:16:01.680 --> 00:16:04.870
merging. Uh that's that's probably been


00:16:04.880 --> 00:16:07.030
the commonest source of gravitational


00:16:07.040 --> 00:16:08.710
waves. There've been several of those.


00:16:08.720 --> 00:16:10.389
We've had a couple of neutron stars


00:16:10.399 --> 00:16:12.790
merging as well. And that actually comes


00:16:12.800 --> 00:16:15.189
with celestial fireworks that you can


00:16:15.199 --> 00:16:18.069
observe with other types of telescope


00:16:18.079 --> 00:16:20.150
like neutrino telescopes, visible light


00:16:20.160 --> 00:16:22.230
telescopes, radio telescopes, x-ray


00:16:22.240 --> 00:16:25.110
telescopes, all of the above. Um and


00:16:25.120 --> 00:16:27.509
that was a big story actually late last


00:16:27.519 --> 00:16:30.629
year if I remember rightly. But um until


00:16:30.639 --> 00:16:34.629
now we haven't had a confirmed um uh


00:16:34.639 --> 00:16:36.790
observation of a neutron star being


00:16:36.800 --> 00:16:38.310
absorbed by a black hole and we still


00:16:38.320 --> 00:16:41.509
don't have it's still a bit speculative


00:16:41.519 --> 00:16:44.069
but from the masses that are inferred by


00:16:44.079 --> 00:16:45.749
the signal and remember what you get is


00:16:45.759 --> 00:16:49.670
this weird gravitational chirp uh it's


00:16:49.680 --> 00:16:53.110
the frequency of a sound wave going


00:16:53.120 --> 00:16:55.749
as the two things come together. Um, and


00:16:55.759 --> 00:16:57.590
it's that that gives you all the details


00:16:57.600 --> 00:16:59.829
of what it is that that are colliding.


00:16:59.839 --> 00:17:02.389
The suspicion is it's two objects, one


00:17:02.399 --> 00:17:05.510
of which is three solar masses and the


00:17:05.520 --> 00:17:09.350
other is five solar masses. I think I'm


00:17:09.360 --> 00:17:11.669
right in saying that. I uh should check


00:17:11.679 --> 00:17:14.870
those numbers. But anyway, uh that is


00:17:14.880 --> 00:17:17.590
the current uh expectation of what is


00:17:17.600 --> 00:17:20.150
colliding. So something three solar


00:17:20.160 --> 00:17:23.270
masses would have to be a neutron star


00:17:23.280 --> 00:17:26.870
because it's too lightweight uh to be a


00:17:26.880 --> 00:17:29.990
black hole. And so that is what's making


00:17:30.000 --> 00:17:33.830
this interesting. What's what's perhaps


00:17:33.840 --> 00:17:36.310
um a bit surprising


00:17:36.320 --> 00:17:39.909
uh it's is that you might expect there


00:17:39.919 --> 00:17:42.310
to be once again uh radiation coming


00:17:42.320 --> 00:17:43.669
from this of you know not just


00:17:43.679 --> 00:17:46.870
gravitational radiation but uh noise in


00:17:46.880 --> 00:17:50.310
the x-ray spectrum or neutron neutrinos


00:17:50.320 --> 00:17:52.870
uh particles things of that sort but it


00:17:52.880 --> 00:17:57.669
but it hasn't been observed and um the


00:17:57.679 --> 00:18:00.870
one of the Australian astronomers uh Um


00:18:00.880 --> 00:18:02.150
I've forgotten her first name. That's


00:18:02.160 --> 00:18:04.310
embarrassing, isn't it? Susan Susan


00:18:04.320 --> 00:18:07.669
Scott. Uh she's at um ANU, Australian


00:18:07.679 --> 00:18:12.470
National University. Uh she says that uh


00:18:12.480 --> 00:18:14.549
I if she well what she says is we've


00:18:14.559 --> 00:18:15.990
looked for light signatures of the


00:18:16.000 --> 00:18:17.590
event, but no one has found any up to


00:18:17.600 --> 00:18:19.909
this point. That indicates that if it is


00:18:19.919 --> 00:18:22.310
a black hole and a neutron star, then


00:18:22.320 --> 00:18:24.710
very likely the neutron star has been


00:18:24.720 --> 00:18:27.830
swallowed whole by the black hole. Uh uh


00:18:27.840 --> 00:18:29.990
he said and she says this could happen


00:18:30.000 --> 00:18:32.870
if the objects were of different masses.


00:18:32.880 --> 00:18:35.350
So it's the smaller object gets sucked


00:18:35.360 --> 00:18:37.029
in more quickly and and is swallowed


00:18:37.039 --> 00:18:39.029
whole. So you know it's not strung out


00:18:39.039 --> 00:18:43.190
into into this um mess of material uh


00:18:43.200 --> 00:18:46.710
that does emit um signals in the


00:18:46.720 --> 00:18:49.909
electromagnetic uh wave bands. Uh if it


00:18:49.919 --> 00:18:52.230
gets sucked in hole maybe you don't get


00:18:52.240 --> 00:18:53.909
any signal at all except for the


00:18:53.919 --> 00:18:55.350
gravitational wave signal.


00:18:55.360 --> 00:18:55.750
extraordinary.


00:18:55.760 --> 00:18:59.190
>> How how sudden would the impact be? I


00:18:59.200 --> 00:19:01.669
mean, you know, neutron stars, we've


00:19:01.679 --> 00:19:03.830
talked about them, and they're pretty


00:19:03.840 --> 00:19:06.549
volatile individuals and and quite


00:19:06.559 --> 00:19:08.630
dense. Um,


00:19:08.640 --> 00:19:10.870
>> quite quite dense is just a slight


00:19:10.880 --> 00:19:12.870
understatement there.


00:19:12.880 --> 00:19:16.310
>> Yes, indeed. Um, so, so


00:19:16.320 --> 00:19:18.549
I imagine it would be quite a cathlymic


00:19:18.559 --> 00:19:19.350
collision.


00:19:19.360 --> 00:19:22.390
>> Yeah, that's right. Um in fact so when


00:19:22.400 --> 00:19:25.110
you've got two black holes um what you


00:19:25.120 --> 00:19:26.789
get at the end of it is a more massive


00:19:26.799 --> 00:19:28.150
black hole


00:19:28.160 --> 00:19:30.950
>> uh and um you're talking there though


00:19:30.960 --> 00:19:32.710
about


00:19:32.720 --> 00:19:34.549
you know infinitely small infinite


00:19:34.559 --> 00:19:37.350
decimally small points merging uh their


00:19:37.360 --> 00:19:39.830
event horizon there are two event


00:19:39.840 --> 00:19:41.830
horizons merge as well and you get


00:19:41.840 --> 00:19:43.190
something called a ring down where the


00:19:43.200 --> 00:19:45.990
event horizon itself vibrates


00:19:46.000 --> 00:19:48.470
um I think with a neutron star you


00:19:48.480 --> 00:19:50.230
wouldn't have the event horizon


00:19:50.240 --> 00:19:52.070
But it will be possible for the the


00:19:52.080 --> 00:19:54.070
neutron star just basically to disappear


00:19:54.080 --> 00:19:55.830
over the black holes event horizon. You


00:19:55.840 --> 00:19:58.150
don't see anything. But neutron stars


00:19:58.160 --> 00:19:59.430
themselves as you and I have talked


00:19:59.440 --> 00:20:01.270
about many times are active in the sense


00:20:01.280 --> 00:20:03.430
that they've got highly intense magnetic


00:20:03.440 --> 00:20:05.990
fields on their surfaces and they beam


00:20:06.000 --> 00:20:08.390
this radiation out which we see as as


00:20:08.400 --> 00:20:10.549
pulsars. So they're not they're not


00:20:10.559 --> 00:20:12.950
particularly quiet things. I mean, this


00:20:12.960 --> 00:20:15.750
thing could be a pulsar whose lighthouse


00:20:15.760 --> 00:20:18.310
beam of radiation is missing the Earth,


00:20:18.320 --> 00:20:20.390
if if I can put it that way, because the


00:20:20.400 --> 00:20:22.230
only reason we see pulsars is when


00:20:22.240 --> 00:20:25.510
you've got a neutron star whose uh beams


00:20:25.520 --> 00:20:27.510
of radiation from their poles actually


00:20:27.520 --> 00:20:29.190
sweeps across the Earth. And that, of


00:20:29.200 --> 00:20:31.750
course, is a particular uh circumstance.


00:20:31.760 --> 00:20:34.630
Maybe this one wasn't like that and it's


00:20:34.640 --> 00:20:37.350
just got chewed up uh and we haven't kn


00:20:37.360 --> 00:20:39.909
we haven't seen it its demise other than


00:20:39.919 --> 00:20:41.830
in the gravitational waves. I think


00:20:41.840 --> 00:20:43.750
there'll be more about this story Andrew


00:20:43.760 --> 00:20:46.070
and um I hope you and I can bring it to


00:20:46.080 --> 00:20:48.950
our uh our space nuts listener or


00:20:48.960 --> 00:20:50.070
listeners


00:20:50.080 --> 00:20:52.549
>> our fraternity.


00:20:52.559 --> 00:20:55.909
>> Yes. Uh well it's it um you know the the


00:20:55.919 --> 00:20:58.710
more we can gather in terms of data uh


00:20:58.720 --> 00:21:01.350
on gravitational waves the the more we


00:21:01.360 --> 00:21:04.549
will learn and who knows what sort of


00:21:04.559 --> 00:21:06.149
problems it could solve down the track.


00:21:06.159 --> 00:21:07.110
So


00:21:07.120 --> 00:21:09.430
>> exactly it's always my comment that you


00:21:09.440 --> 00:21:11.270
never know what you're what you've


00:21:11.280 --> 00:21:13.029
setting in store for the future from all


00:21:13.039 --> 00:21:13.990
this knowledge.


00:21:14.000 --> 00:21:16.230
>> Exactly. Yeah. I mean you just gather


00:21:16.240 --> 00:21:18.470
the knowledge one day it might just go


00:21:18.480 --> 00:21:19.990
you know a penny will drop with someone


00:21:20.000 --> 00:21:21.190
else maybe


00:21:21.200 --> 00:21:23.110
>> a generation down the track. Who knows?


00:21:23.120 --> 00:21:24.870
It's it's all useful.


00:21:24.880 --> 00:21:26.549
>> And even if it's not, it's good to be


00:21:26.559 --> 00:21:28.149
able to gather it and


00:21:28.159 --> 00:21:30.870
>> well, they use it some some way.


00:21:30.880 --> 00:21:32.950
>> It it's um you know, all these things


00:21:32.960 --> 00:21:34.950
are constantly testing Einstein's theory


00:21:34.960 --> 00:21:38.470
of relativity. And that's um very


00:21:38.480 --> 00:21:39.750
important because we know there's


00:21:39.760 --> 00:21:40.870
something wrong with it, but we haven't


00:21:40.880 --> 00:21:42.710
found anything wrong with it yet. Even


00:21:42.720 --> 00:21:44.390
though it's been tested within an inch


00:21:44.400 --> 00:21:47.110
of its life, it still holds up.


00:21:47.120 --> 00:21:49.510
>> Yeah. Fascinating. All right. Stop.


00:21:49.520 --> 00:21:51.110
>> You're listening to the Space Nuts


00:21:51.120 --> 00:21:53.430
podcast with Andrew Dunley and Fred


00:21:53.440 --> 00:21:56.549
Watson.


00:21:56.559 --> 00:21:58.710
>> Okay, we checked all four systems and


00:21:58.720 --> 00:21:59.510
being with the girls.


00:21:59.520 --> 00:22:00.390
>> Space Nuts.


00:22:00.400 --> 00:22:02.310
>> Now, Fred, I do want to shout out once


00:22:02.320 --> 00:22:06.310
again to our patrons. Uh, the number 39


00:22:06.320 --> 00:22:08.710
now. Uh, thank you so much for


00:22:08.720 --> 00:22:11.110
supporting the Space Nuts podcast. We so


00:22:11.120 --> 00:22:13.029
appreciate it. And if you're interested


00:22:13.039 --> 00:22:15.350
in becoming a patron, you can do so at


00:22:15.360 --> 00:22:17.909
patreon.com/spacenuts.


00:22:17.919 --> 00:22:21.669
That's patreon.com/spacenuts.


00:22:21.679 --> 00:22:24.310
And uh thank you to everybody who has


00:22:24.320 --> 00:22:27.270
joined the Spacenuts podcast group. They


00:22:27.280 --> 00:22:29.669
number in their hundreds now, Fred.


00:22:29.679 --> 00:22:31.669
>> We've only had the page going for a bit


00:22:31.679 --> 00:22:33.909
over a week and already we've we've


00:22:33.919 --> 00:22:35.669
tracked the century.


00:22:35.679 --> 00:22:38.630
>> And have over 100 people that are all


00:22:38.640 --> 00:22:40.870
Space Nuts fans who are all now talking


00:22:40.880 --> 00:22:42.789
to each other and uh answering each


00:22:42.799 --> 00:22:45.270
other's questions and uh having a fair


00:22:45.280 --> 00:22:47.430
bit of fun. So, it's I'm so pleased we


00:22:47.440 --> 00:22:49.830
were able to put um those people


00:22:49.840 --> 00:22:51.590
together and uh who knows friends


00:22:51.600 --> 00:22:54.230
friendships may be forged


00:22:54.240 --> 00:22:56.630
>> um or collaborations that might solve


00:22:56.640 --> 00:22:58.070
some of the mysteries of the universe.


00:22:58.080 --> 00:23:00.390
Who knows? Uh that would be a lovely


00:23:00.400 --> 00:23:03.110
legacy. I think uh let's um


00:23:03.120 --> 00:23:05.669
>> and of course if you would like to be a


00:23:05.679 --> 00:23:07.669
uh a member of the Space Nuts podcast


00:23:07.679 --> 00:23:10.630
group um just find it. It's on Facebook


00:23:10.640 --> 00:23:12.310
uh Space Nuts podcast group in your


00:23:12.320 --> 00:23:14.789
search engine. And um yes, just ask to


00:23:14.799 --> 00:23:17.110
join and we will click the approve


00:23:17.120 --> 00:23:19.110
button. Everybody seems to be


00:23:19.120 --> 00:23:21.029
like-minded and enjoying themselves. So


00:23:21.039 --> 00:23:23.430
uh that's what it's all about.


00:23:23.440 --> 00:23:27.110
Now Fred, some questions, if you will.


00:23:27.120 --> 00:23:29.750
Um hello again, fellow nutters. I have a


00:23:29.760 --> 00:23:32.310
question. I'm hoping you can help me um


00:23:32.320 --> 00:23:35.110
understanding an old chestnut. Black


00:23:35.120 --> 00:23:37.669
holes. If a black hole is an infinite


00:23:37.679 --> 00:23:39.510
dense point, why does it have a


00:23:39.520 --> 00:23:41.350
diameter? I don't understand why


00:23:41.360 --> 00:23:43.190
astronomers refer to black holes by


00:23:43.200 --> 00:23:45.190
their size in terms of diameter when


00:23:45.200 --> 00:23:47.350
it's meant to be a point of infinite des


00:23:47.360 --> 00:23:49.669
uh density. Are they mistakenly


00:23:49.679 --> 00:23:52.390
referring to the event horizon? Mario


00:23:52.400 --> 00:23:54.470
from Melbourne. Hello Mario. Thanks for


00:23:54.480 --> 00:23:57.110
the question. And the answer is yes.


00:23:57.120 --> 00:23:58.549
Thank you Mario. Thanks for the


00:23:58.559 --> 00:24:02.390
question. Um Mario then goes on to you


00:24:02.400 --> 00:24:04.789
know everything he says is absolutely


00:24:04.799 --> 00:24:07.830
right that um uh if you've got a a a


00:24:07.840 --> 00:24:10.310
point of infinite density it's got zero


00:24:10.320 --> 00:24:13.110
dimensions so you can't refer to its


00:24:13.120 --> 00:24:15.909
diameter. Uh what you can refer to is


00:24:15.919 --> 00:24:19.190
its mass because the the mass is uh is


00:24:19.200 --> 00:24:22.710
variable. uh but the fact that it has no


00:24:22.720 --> 00:24:25.269
volume means that when you you know when


00:24:25.279 --> 00:24:26.789
you look at the mass per unit volume


00:24:26.799 --> 00:24:28.470
you've got something of infinite density


00:24:28.480 --> 00:24:31.110
which is how density is defined. So


00:24:31.120 --> 00:24:33.830
Mario is absolutely right. Uh what does


00:24:33.840 --> 00:24:36.310
vary though with the mass is the event


00:24:36.320 --> 00:24:37.909
horizon the diameter of the event


00:24:37.919 --> 00:24:39.269
horizon which you and I have spoken


00:24:39.279 --> 00:24:44.230
about before. Um it's uh uh it's a a


00:24:44.240 --> 00:24:47.750
quantity that I I suppose is important


00:24:47.760 --> 00:24:51.269
because if we are observing an um a


00:24:51.279 --> 00:24:53.029
black hole as we did with the event


00:24:53.039 --> 00:24:54.549
horizon telescope then that's what you


00:24:54.559 --> 00:24:56.549
see. Uh so a big one's going to be


00:24:56.559 --> 00:24:58.149
easier to observe than a smaller one and


00:24:58.159 --> 00:25:00.310
that's why a super massive black hole uh


00:25:00.320 --> 00:25:02.710
in the center of a galaxy called M87 was


00:25:02.720 --> 00:25:04.870
chosen for the the first target for that


00:25:04.880 --> 00:25:07.110
event horizon telescope. But no Mario


00:25:07.120 --> 00:25:09.909
you're quite right. Um it is that uh


00:25:09.919 --> 00:25:11.590
astronomers when if they talk about the


00:25:11.600 --> 00:25:13.190
diameter of a black hole and that


00:25:13.200 --> 00:25:15.510
probably includes me as well uh are


00:25:15.520 --> 00:25:17.190
actually really referring to the event


00:25:17.200 --> 00:25:18.870
horizon because that's the that's the


00:25:18.880 --> 00:25:21.350
parameter. And I love the way Mario


00:25:21.360 --> 00:25:23.430
signs off by saying thanks in advance to


00:25:23.440 --> 00:25:26.950
Dave and Fred although he does say aka


00:25:26.960 --> 00:25:28.070
Andrew.


00:25:28.080 --> 00:25:29.590
>> Yes, that one's going to stick for a


00:25:29.600 --> 00:25:35.110
while. Sorry to say. Thank you Mario.


00:25:35.120 --> 00:25:37.590
Moving on. Uh hi Andrew and Fred. It's


00:25:37.600 --> 00:25:39.350
Andrew from Newcastle with another


00:25:39.360 --> 00:25:41.830
question if I may. Just watched a doco


00:25:41.840 --> 00:25:43.430
on the quest to capture the first


00:25:43.440 --> 00:25:45.909
photograph of a black hole. Uh rather


00:25:45.919 --> 00:25:48.070
accurately the shadow of a black hole as


00:25:48.080 --> 00:25:50.390
Fred so eloquently explained and I


00:25:50.400 --> 00:25:53.029
didn't understand one thing amongst


00:25:53.039 --> 00:25:54.789
others of course with the multiple


00:25:54.799 --> 00:25:56.470
observatories around the world and the


00:25:56.480 --> 00:25:58.390
use of atomic clocks to synchronize the


00:25:58.400 --> 00:26:01.669
data acquisition. Why were they uh on


00:26:01.679 --> 00:26:04.710
tender hooks uh regarding the weather at


00:26:04.720 --> 00:26:07.029
all the sites with bad weather at just


00:26:07.039 --> 00:26:09.110
one putting the whole venture in peril?


00:26:09.120 --> 00:26:11.190
I understand from the show and other


00:26:11.200 --> 00:26:13.110
sources that they were collecting radio


00:26:13.120 --> 00:26:15.510
wavelength data and I thought that this


00:26:15.520 --> 00:26:17.350
was unaffected by the weather and


00:26:17.360 --> 00:26:19.909
atmospheric conditions. I thought that


00:26:19.919 --> 00:26:22.070
was the intrinsic beauty of radio


00:26:22.080 --> 00:26:24.470
astronomy day and night rain and shine.


00:26:24.480 --> 00:26:27.430
Hope you can enlighten me. Wait for it


00:26:27.440 --> 00:26:30.390
but over the radio. Dear, oh dear. H


00:26:30.400 --> 00:26:32.710
Andrew Broadhost. Thank you, Andrew.


00:26:32.720 --> 00:26:34.149
>> That's a great question, Andrew. Leave


00:26:34.159 --> 00:26:37.830
the jokes to me, man.


00:26:37.840 --> 00:26:39.669
>> Yeah. Well, I always leave them to you.


00:26:39.679 --> 00:26:41.669
So,


00:26:41.679 --> 00:26:43.669
>> um if they're good.


00:26:43.679 --> 00:26:45.990
>> Oh gosh. When was the last Oh, never


00:26:46.000 --> 00:26:47.990
mind.


00:26:48.000 --> 00:26:49.909
Uh Andrew's on the money there is, you


00:26:49.919 --> 00:26:51.430
know, I thought radio waves were


00:26:51.440 --> 00:26:53.269
unaffected by the weather. And the


00:26:53.279 --> 00:26:54.870
answer is that radio waves come in


00:26:54.880 --> 00:26:58.149
different flavors. Uh and so what you


00:26:58.159 --> 00:27:01.029
might call low frequency radio waves um


00:27:01.039 --> 00:27:03.510
which are still relatively you know


00:27:03.520 --> 00:27:05.590
they're way outside the medium wave band


00:27:05.600 --> 00:27:07.990
of radio and things of that sort but low


00:27:08.000 --> 00:27:10.870
frequency in radio astronomy um I guess


00:27:10.880 --> 00:27:12.789
goes up to a couple of gigahertz or


00:27:12.799 --> 00:27:15.750
something like that. Um those are


00:27:15.760 --> 00:27:17.990
largely unaffected by weather. That's


00:27:18.000 --> 00:27:19.669
absolutely right. So that's why it can


00:27:19.679 --> 00:27:21.990
be pouring down at parks at the radio


00:27:22.000 --> 00:27:23.669
dish there and the astronomers are still


00:27:23.679 --> 00:27:25.909
happily observing through that. But the


00:27:25.919 --> 00:27:27.830
event horizon telescope used higher


00:27:27.840 --> 00:27:31.029
frequencies. Uh in fact one of the


00:27:31.039 --> 00:27:33.190
telescopes that was incorporated into it


00:27:33.200 --> 00:27:35.669
was ALMA the Atakama large millimeter


00:27:35.679 --> 00:27:38.470
array which has featured very uh very


00:27:38.480 --> 00:27:40.950
widely on space notes. That is a high


00:27:40.960 --> 00:27:42.630
frequency


00:27:42.640 --> 00:27:46.149
uh radio array. In fact they have


00:27:46.159 --> 00:27:49.350
receivers that go up to uh more than 900


00:27:49.360 --> 00:27:51.350
gigahertz. So that's like, you know,


00:27:51.360 --> 00:27:53.350
nearly a thousand times higher


00:27:53.360 --> 00:27:54.870
frequencies than what we've just been


00:27:54.880 --> 00:27:56.950
talking about. And at those sorts of


00:27:56.960 --> 00:27:59.909
frequencies, uh, the weather plays a


00:27:59.919 --> 00:28:02.870
very important role because water vapor


00:28:02.880 --> 00:28:05.510
actually dramatically absorbs the


00:28:05.520 --> 00:28:07.990
microwave signals. And that's what


00:28:08.000 --> 00:28:09.510
experienced that watching satellite


00:28:09.520 --> 00:28:12.950
television. If there is a storm and it


00:28:12.960 --> 00:28:14.789
rains heavily, the wavelengths of the


00:28:14.799 --> 00:28:17.029
raindrops can absorb the signals from


00:28:17.039 --> 00:28:19.750
the satellite and you get nothing.


00:28:19.760 --> 00:28:21.590
That's interesting. I've never tried to


00:28:21.600 --> 00:28:24.149
watch satellite television, so that's


00:28:24.159 --> 00:28:25.430
good thing to know.


00:28:25.440 --> 00:28:26.230
>> Um,


00:28:26.240 --> 00:28:27.990
>> it's one of the pitfalls.


00:28:28.000 --> 00:28:29.750
>> Yes. Yes. In fact, I seldom watch


00:28:29.760 --> 00:28:31.510
television at all. So, that's probably


00:28:31.520 --> 00:28:35.269
why. Um, but but the bottom line is um,


00:28:35.279 --> 00:28:38.549
you know, it's why facilities like ALMA


00:28:38.559 --> 00:28:40.789
and some of the other radio telescopes


00:28:40.799 --> 00:28:44.389
that were used uh to to to be become the


00:28:44.399 --> 00:28:45.750
event horizon telescope, it's why


00:28:45.760 --> 00:28:48.070
they're all at high altitudes. Alma is


00:28:48.080 --> 00:28:51.830
at almost 5,000 meters above sea level.


00:28:51.840 --> 00:28:55.430
Um that's you know 15 16,000 feet and at


00:28:55.440 --> 00:28:57.750
that height there is very little water


00:28:57.760 --> 00:28:59.990
vapor in the atmosphere. Uh but you can


00:29:00.000 --> 00:29:01.830
still get weather and that's why they


00:29:01.840 --> 00:29:03.590
were indeed on tent hooks about the


00:29:03.600 --> 00:29:05.269
weather because they don't want any of


00:29:05.279 --> 00:29:09.110
these if you lose one of those arrays


00:29:09.120 --> 00:29:10.310
and I think there were eight of them


00:29:10.320 --> 00:29:12.070
that came together all around one


00:29:12.080 --> 00:29:14.870
hemisphere of the earth uh to to to make


00:29:14.880 --> 00:29:17.029
up the event horizon telescope. if you


00:29:17.039 --> 00:29:19.430
lose one of them, you lose a significant


00:29:19.440 --> 00:29:21.350
amount of your ability to reconstruct


00:29:21.360 --> 00:29:23.590
the image that they're seeing. Uh, and


00:29:23.600 --> 00:29:25.269
so that was why they were worried that


00:29:25.279 --> 00:29:26.870
the the weather on just one of them


00:29:26.880 --> 00:29:30.230
might be uh moist uh or damper than they


00:29:30.240 --> 00:29:31.669
can cope with and that would have


00:29:31.679 --> 00:29:33.269
screwed up the whole thing. But as it


00:29:33.279 --> 00:29:35.110
happened, it wasn't. It didn't happen


00:29:35.120 --> 00:29:36.549
and it was great.


00:29:36.559 --> 00:29:38.549
>> They got global good weather.


00:29:38.559 --> 00:29:40.149
>> They did global good weather at these


00:29:40.159 --> 00:29:41.510
high altitude sites. That's right.


00:29:41.520 --> 00:29:42.950
>> Did the job. All right, there you are,


00:29:42.960 --> 00:29:45.909
Andrew. Uh, thank you for your question.


00:29:45.919 --> 00:29:47.909
And we've got one more we'll squeeze in


00:29:47.919 --> 00:29:50.710
from John Spoo. I hope I pronounced that


00:29:50.720 --> 00:29:52.070
correctly. John, thanks for your


00:29:52.080 --> 00:29:53.669
question. Hi, I have a question that's


00:29:53.679 --> 00:29:55.430
been bugging me for some time and I need


00:29:55.440 --> 00:29:58.310
an expert to help me out. I think we


00:29:58.320 --> 00:30:00.230
should stop there, Fred.


00:30:00.240 --> 00:30:01.830
>> There's nobody here, is there? Who's


00:30:01.840 --> 00:30:03.190
that? Hang on, I'll go and see if I can


00:30:03.200 --> 00:30:04.149
find somebody.


00:30:04.159 --> 00:30:05.909
>> Maybe the cat could probably answer this


00:30:05.919 --> 00:30:09.190
one. Now, um, imagine a spaceship


00:30:09.200 --> 00:30:11.110
traveling close to the speed of light.


00:30:11.120 --> 00:30:12.710
Disregarding that we don't have that


00:30:12.720 --> 00:30:15.029
sort of propulsion just yet, would the


00:30:15.039 --> 00:30:18.870
increase in its relativistic mass at


00:30:18.880 --> 00:30:20.789
some point turn the spaceship into a


00:30:20.799 --> 00:30:24.070
black hole? And if so, would that spell


00:30:24.080 --> 00:30:26.070
the end of the ship and its crew? Or


00:30:26.080 --> 00:30:27.990
would they be able to slow down to


00:30:28.000 --> 00:30:30.389
reverse the process? What a great


00:30:30.399 --> 00:30:30.870
question.


00:30:30.880 --> 00:30:32.470
>> It is a fantastic question. Do you want


00:30:32.480 --> 00:30:33.669
to have a go at it?


00:30:33.679 --> 00:30:35.909
>> Uh, the answer is no.


00:30:35.919 --> 00:30:37.830
>> It is. You got right. Yeah, you were


00:30:37.840 --> 00:30:39.190
right on the money there. See, see,


00:30:39.200 --> 00:30:40.789
there is an expert. It's called Andrew


00:30:40.799 --> 00:30:42.630
Dunley or Dave


00:30:42.640 --> 00:30:45.750
>> 50/50 chance.


00:30:45.760 --> 00:30:49.510
>> Um, it's a great question and it it the


00:30:49.520 --> 00:30:52.630
answer is a little bit prosaic I think


00:30:52.640 --> 00:30:55.990
and that is that in the in the rest


00:30:56.000 --> 00:30:58.149
frame of the spacecraft


00:30:58.159 --> 00:30:59.990
you know so if you're on the spacecraft


00:31:00.000 --> 00:31:01.590
and you're going at almost the speed of


00:31:01.600 --> 00:31:05.110
light your mass doesn't change. It's


00:31:05.120 --> 00:31:09.110
only in the rest frame of a a stationary


00:31:09.120 --> 00:31:10.549
observer. And by that I mean somebody


00:31:10.559 --> 00:31:12.789
watching you go past. Somebody watches


00:31:12.799 --> 00:31:15.830
you hurl past and your mass gets very


00:31:15.840 --> 00:31:19.110
much higher to the observer.


00:31:19.120 --> 00:31:22.389
>> But to the the inhabitants of the


00:31:22.399 --> 00:31:24.470
spacecraft or the spacecraft itself,


00:31:24.480 --> 00:31:25.669
your mass doesn't change.


00:31:25.679 --> 00:31:27.590
>> It's you're still normal.


00:31:27.600 --> 00:31:29.830
>> Still normal. Yeah. So and the same


00:31:29.840 --> 00:31:31.909
story is true with time dilation. You


00:31:31.919 --> 00:31:33.909
know you're you know that when you go


00:31:33.919 --> 00:31:36.230
nearer the speed of light, your clocks


00:31:36.240 --> 00:31:39.110
tick slower. Uh that's a scene by a


00:31:39.120 --> 00:31:41.909
stationary observer. Uh and so it's the


00:31:41.919 --> 00:31:43.190
same sort of thing. If you're on the


00:31:43.200 --> 00:31:44.789
spacecraft, your clock is ticking at the


00:31:44.799 --> 00:31:46.789
same rate as it ever was. But to a


00:31:46.799 --> 00:31:48.470
stationary observer, your clocks tick


00:31:48.480 --> 00:31:48.950
slower.


00:31:48.960 --> 00:31:50.710
>> And this has been proven with atomic


00:31:50.720 --> 00:31:51.830
clocks, hasn't it?


00:31:51.840 --> 00:31:53.909
>> It has. And indeed with mass as well.


00:31:53.919 --> 00:31:55.669
You can do this. You can see this sort


00:31:55.679 --> 00:31:59.350
of phenomenon with um uh with uh cosmic


00:31:59.360 --> 00:32:01.269
rays which travel very close to the


00:32:01.279 --> 00:32:02.630
speed of light. You can see their mass


00:32:02.640 --> 00:32:06.230
change. So, um, that's from the point of


00:32:06.240 --> 00:32:08.230
view of somebody who's, you know, not


00:32:08.240 --> 00:32:09.990
moving at the same speed. If you're


00:32:10.000 --> 00:32:11.750
moving at the same speed, you don't see


00:32:11.760 --> 00:32:13.750
any change at all.


00:32:13.760 --> 00:32:14.789
>> That's pretty boring.


00:32:14.799 --> 00:32:16.950
>> I mean, the more the more we discuss


00:32:16.960 --> 00:32:18.630
black holes and the number of questions


00:32:18.640 --> 00:32:21.350
we get about them, people are really


00:32:21.360 --> 00:32:25.029
quite captivated by the strangeness of


00:32:25.039 --> 00:32:27.110
them. I suppose they they throw up all


00:32:27.120 --> 00:32:29.750
these things that seem so alien to what


00:32:29.760 --> 00:32:32.230
we consider normal. Uh, and that's


00:32:32.240 --> 00:32:35.110
because we've only experienced uh what's


00:32:35.120 --> 00:32:37.269
happening on our planet any given time.


00:32:37.279 --> 00:32:40.789
So to to try and comprehend um enough


00:32:40.799 --> 00:32:44.470
gravity to warp time to slow things down


00:32:44.480 --> 00:32:46.950
to the observer and and increase mass


00:32:46.960 --> 00:32:50.870
just it's really whack.


00:32:50.880 --> 00:32:52.950
Sad on the brain. That's true. And you


00:32:52.960 --> 00:32:55.110
know, but uh look, John's question there


00:32:55.120 --> 00:32:57.750
is is a great question because it's it's


00:32:57.760 --> 00:33:00.549
not intuitively obvious what is


00:33:00.559 --> 00:33:03.110
happening uh in a situation like


00:33:03.120 --> 00:33:04.470
something traveling close to the speed


00:33:04.480 --> 00:33:07.669
of light and and so he's right to ask


00:33:07.679 --> 00:33:09.909
would that mass actually turn it into a


00:33:09.919 --> 00:33:11.909
black hole? Uh but the answer is no


00:33:11.919 --> 00:33:12.950
because of the reasons that I've


00:33:12.960 --> 00:33:14.710
outlined. But it's great great thinking.


00:33:14.720 --> 00:33:16.230
>> It is indeed. Thank you, John. Thanks


00:33:16.240 --> 00:33:18.230
for the question. Do appreciate it. Keep


00:33:18.240 --> 00:33:19.669
your questions coming in. We're trying


00:33:19.679 --> 00:33:22.310
to um run them down, but they it's it's


00:33:22.320 --> 00:33:25.509
it's an ever growing mass really.


00:33:25.519 --> 00:33:27.509
>> It's all right. Look, as you said


00:33:27.519 --> 00:33:29.430
earlier, Andrew, um all the space


00:33:29.440 --> 00:33:30.870
nutters are going to get together and


00:33:30.880 --> 00:33:32.870
sort them out for themselves and we'll


00:33:32.880 --> 00:33:34.070
be


00:33:34.080 --> 00:33:35.909
>> encourage actually if uh if people want


00:33:35.919 --> 00:33:39.029
to ask questions of the group and and


00:33:39.039 --> 00:33:41.590
discuss it, they Yeah, by all means. Um


00:33:41.600 --> 00:33:43.350
that that's part of the reason we set up


00:33:43.360 --> 00:33:45.830
the Space Nuts podcast group. So, um,


00:33:45.840 --> 00:33:48.389
it's a good opportunity to not only meet


00:33:48.399 --> 00:33:50.630
like-minded people who enjoy these these


00:33:50.640 --> 00:33:52.389
topics, but also to maybe come up with


00:33:52.399 --> 00:33:54.870
your own ideas on on what might be. And,


00:33:54.880 --> 00:33:56.310
you know, I'll keep an eye on it, and if


00:33:56.320 --> 00:33:57.830
something pops in there that we think is


00:33:57.840 --> 00:34:00.310
worthy of further discussion, we will


00:34:00.320 --> 00:34:03.110
certainly investigate that. Uh, thanks


00:34:03.120 --> 00:34:05.590
to everyone who um who who sent in their


00:34:05.600 --> 00:34:08.470
questions uh and contributed and joined


00:34:08.480 --> 00:34:10.790
the Space Nuts podcast group and Patreon


00:34:10.800 --> 00:34:11.909
and everything else. We really


00:34:11.919 --> 00:34:14.149
appreciate it. Uh but most of all we


00:34:14.159 --> 00:34:16.470
appreciate you Fred. Thank you so much.


00:34:16.480 --> 00:34:18.550
>> It's a pleasure. Thank you for having me


00:34:18.560 --> 00:34:19.430
as always.


00:34:19.440 --> 00:34:21.510
>> And we will catch you next week.


00:34:21.520 --> 00:34:24.149
Professor Fred Watson, uh astronomer at


00:34:24.159 --> 00:34:26.149
large. And from me, Andrew Dunley, thank


00:34:26.159 --> 00:34:28.069
you again and we'll catch you next time


00:34:28.079 --> 00:34:30.869
on another edition of Space Nuts.


00:34:30.879 --> 00:34:31.909
>> Space Nuts.


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>> You've been listening to the Space Nuts


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podcast


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>> available at Apple Podcasts, Spotify,


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iHeart Radio, or your favorite podcast


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player. You can also stream on demand at


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byes.com. This has been another quality


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podcast production from byes.com.